| 1. |
- Abafe, Ovokeroye A., et al.
(författare)
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LC-MS/MS determination of antiretroviral drugs in influents and effluents from wastewater treatment plants in KwaZulu-Natal, South Africa
- 2018
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 200, s. 660-670
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Tidskriftsartikel (refereegranskat)abstract
- South Africa has the largest occurrence of the human immune deficiency virus (HIV) in the world but has also implemented the largest antiretroviral (ARV) treatment programme. It was therefore of interest to determine the presence and concentrations of commonly used antiretroviral drugs (ARVDs) and, also, to determine the capabilities of wastewater treatment plants (WWTPs) for removing ARVDs. To this end, a surrogate standard based LC-MS/MS method was optimized and applied for the detection of thirteen ARVDs used in the treatment and management of HIV/acquired immune deficiency syndrome (HIV/AIDS) in two major and one modular WWTP in the eThekwini Municipality in KwaZulu-Natal, South Africa. The method was validated and the detection limits fell within the range of 2–20 ng L−1. The analytical recoveries for the ARVDs were mainly greater than 50% with acceptable relative standard deviations. The concentration values ranged from −1 (influent), −1 (effluent) in a decentralized wastewater treatment facility (DEWATS); −1 (influent), −1 (effluent) in Northern WWTP and 61–34000 ng L−1 (influent), −1 (effluent) in Phoenix WWTP. Whilst abacavir, lamivudine and zidovudine were almost completely removed from the effluents, atazanavir, efavirenz, lopinavir and nevirapine persisted in the effluents from all three WWTPs. To estimate the ecotoxicological risks associated with the discharge of ARVDs, a countrywide survey focussing on the occurrence of ARVDs in WWTPs, surface and fresh water bodies, and aquatic organisms, is necessary.
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| 2. |
- Ahmadi, Hamid, et al.
(författare)
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Mass transfer of hydrophobic organic chemicals between siliconesheets and through plant leaves and low-density polyethylene
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 164, s. 683-690
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Tidskriftsartikel (refereegranskat)abstract
- Plant leaves play an important role in the fate of hydrophobic organic contaminants (HOCs) in theenvironment. Yet much remains unknown about the permeability of leaves by HOCs. In this pilot studywe measured (i) the kinetics of mass transfer of three polycyclic aromatic hydrocarbons (PAHs) and sixpolychlorinated biphenyls between a spiked and an unspiked sheet of polydimethylsiloxane (PDMS) indirect contact with each other for 24 h and (ii) kinetics of mass transfer of two PAHs through leaves andlow-density polyethylene (LDPE) in a passive dosing experiment by inserting these matrices between thetwo sheets of PDMS for 48 h. The kinetics of mass transfer of fluoranthene between PDMS sheets in directcontact were a factor of 12 slower than those reported in the literature. The kinetics of mass transfer offluorene and phenanthrene through leaves were within the range of those previously reported for 2,4-dichlorophenoxyacetic acid through isolated cuticles. Our results provide a proof-of-concept demon-stration that the passive dosing method applied in this study can be used to measure the mass transfercoefficients of organic chemicals through leaves. Key recommendations for future experiments are toload the PDMS at the highest feasible concentrations to avoid working at analyte levels close to the limitof detection, to keep the leaves moist and to minimize potential pathways for contamination of the PDMSsheets by exposure to laboratory air.
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| 3. |
- Ahrens, Lutz
(författare)
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Characterization of polyurethane foam (PUF) and sorbent impregnated PUF (SIP) disk passive air samplers for measuring organophosphate flame retardants
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 167, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to characterize the uptake of organophosphate esters (OPEs) by polyurethane foam (PUF) and sorbent-impregnated polyurethane foam (SIP) disk passive air samplers (PAS). Atmospheric OPE concentrations were monitored with high-volume active air samplers (HV-AAS) that were co-deployed with passive air samplers. Samples were analyzed for tris(2-chloroisopropyl) phosphate (TCIPP), tri(phenyl) phosphate (TPhP), tris(2-chloroethyl) phosphate (TCEP), and tris(2,3-dichloropropyl) phosphate (TDCIPP). The mean concentration of Sigma OPES in air was 2650 pg/m(3) for the HV-AAS. Sampling rates and the passive sampler medium (PSM)-air partition coefficient (Kpsm-Air) were calculated for individual OPEs. The average calculated sampling rates (R) for the four OPEs were 3.6 +/- 1.2 and 4.2 +/- 2.0 m(3)/day for the PUF and SIP disks, respectively, and within the range of the recommended default value of 4 +/- 2 m(3)/day. Since most of the OPEs remained in the linear uptake phase during the study, COSMO-RS solvation theory and an oligomer-based model were used to estimate KpuF-Air for the OPEs. The estimated values of log KPUF-Air were 7.45 (TCIPP), 935 (TPhP), 8.44 (TCEP), and 9.67 (TDCIPP). Finally, four configurations of the PUF and SIP disks were tested by adjusting the distance of the gap opening between the upper and lower domes of the sampler housing: i.e. 2 cm, 1 cm, no gap and 1 cm overlap. The sampling rate did not differ significantly between these four configurations (p < 0.05). Crown Copyright (C) 2016 Published by Elsevier Ltd. All rights reserved.
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| 4. |
- Ahrens, Lutz, et al.
(författare)
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Poly- and perfluoroalkylated substances (PFASs) in water, sediment and fish muscle tissue from Lake Tana, Ethiopia and implications for human exposure
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 165, s. 352-357
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Tidskriftsartikel (refereegranskat)abstract
- Lake Tana is Ethiopia's largest lake and there are plans to increase the harvest of fish from the lake. The objective of this study was to assess the levels of poly- and perfluoroalkyl substances (PFASs) in different compartments of the lake (water, sediment, and fish muscle tissue), and its implications for human exposure. The results showed higher PFAS concentrations in piscivorous fish species (Labeobarbus mega-stoma and Labeobarbus gorguari) than non-piscivorous species (Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) and also spatial distribution similarities. The Sigma PFAS concentrations ranged from 0.073 to 5.6 ng L-1 (on average, 2.9 ng L-1) in surface water, 0.22-0.55 ng g(-1) dry weight (dw) (on average, 0.30 ng g(-1) dw) in surface sediment, and non-detected to 5.8 ng g(-1) wet weight (ww) (on average, 1.2 ng g(-1) ww) in all fish species. The relative risk (RR) indicates that the consumption of fish contaminated with perfiuorooctane sulfonate (PFOS) will likely not cause any harmful effects for the Ethiopian fish eating population. However, mixture toxicity of the sum of PFASs, individual fish consumption patterns and increasing fish consumption are important factors to consider in future risk assessments.
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| 5. |
- Ahrens, Lutz, et al.
(författare)
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Stockholm Arlanda Airport as a source of per- and polyfluoroalkyl substances to water, sediment and fish
- 2015
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 129, s. 33-38
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Tidskriftsartikel (refereegranskat)abstract
- Fire training facilities are potential sources of per- and polyfluoroalkyl substances (PFASs) to the nearby environment due to the usage of PFAS-containing aqueous fire-fighting foams (AFFFs). The multimedia distribution of perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs), perfluorooctanesulfonamide (PFOSA) and 6:2 fluorotelomer sulfonate (FFSA) was investigated near a fire training facility at Stockholm Arlanda Airport in Sweden. The whole body burden of PFASs in European perch (Perca fluviatilis) was 334 +/- 80 mu g absolute and was distributed as follows: Gonad > liver approximate to muscle > blood > gill. The bioconcentration factor (BCF) and sediment/water partition coefficient (K-d) increased by 0.6-1.7 and 0.2-0.5 log units, respectively, for each additional CF2 moiety for PFCAs and PFSAs. PFAS concentrations in water showed no significant decreasing trend between 2009 and 2013 (p > 0.05), which indicates that Stockholm Arlanda Airport may be an important source for long-term contamination of the nearby environment with PFASs. (C) 2014 Elsevier Ltd. All rights reserved.
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| 6. |
- Al-Naamani, Laila, et al.
(författare)
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Chitosan-zinc oxide nanocomposite coatings for the prevention of marine biofouling
- 2017
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 168, s. 408-417
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Tidskriftsartikel (refereegranskat)abstract
- Marine biofouling is a worldwide problem affecting maritime industries. Global concerns about the high toxicity of antifouling paints have highlighted the need to develop less toxic antifouling coatings. Chitosan is a natural polymer with antimicrobial, antifungal and antialgal properties that is obtained from partial deacetylation of crustacean waste. In the present study, nanocomposite chitosan-zinc oxide (chitosan-ZnO) nanoparticle hybrid coatings were developed and their antifouling activity was tested. Chitosan-ZnO nanoparticle coatings showed anti-diatom activity against Navicula sp. and antibacterial activity against the marine bacterium Pseudoalteromonas nigrifaciens. Additional antifouling properties of the coatings were investigated in a mesocosm study using tanks containing natural sea water under controlled laboratory conditions. Each week for four weeks, biofilm was removed and analysed by flow cytometry to estimate total bacterial densities on the coated substrates. Chitosan-ZnO hybrid coatings led to better inhibition of bacterial growth in comparison to chitosan coatings alone, as determined by flow cytometry. This study demonstrates the antifouling potential of chitosan-ZnO nanocomposite hybrid coatings, which can be used for the prevention of biofouling. (C) 2016 Elsevier Ltd. All rights reserved.
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| 7. |
- Anbalagan, Anbarasan, et al.
(författare)
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Influence of iron precipitated condition and light intensity on microalgae activated sludge based wastewater remediation
- 2017
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; , s. 1523-1530
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Tidskriftsartikel (refereegranskat)abstract
- The indigenous microalgae-activated sludge (MAAS) process during remediation of municipal wastewater was investigated by studying the influence of iron flocculation step and light intensity. In addition, availability of total phosphorous (P) and photosynthetic activity was examined in fed-batch and batch mode under northern climatic conditions and limited lighting. This was followed by a semi-continuous operation with 4 d of hydraulic retention time and mean cell residence time of 6.75 d in a photo-bioreactor (PBR) with varying P availability. The fed-batch condition showed that P concentrations of 3–4 mg L−1 were effective for photosynthetic chl. a development in iron flocculated conditions. In the PBR, the oxygen evolution rate increased with increase in the concentration of MAAS (from 258 to 573 mg TSS L−1) at higher surface photosynthetic active radiation (250 and 500 μmol m−2 s−1). Additionally, the rate approached a saturation phase at low MAAS (110 mg L−1) with higher light intensities. Semi-continuous operation with luxury P uptake and effective P condition showed stable average total nitrogen removal of 88 and 92% respectively, with residual concentrations of 3.77 and 2.21 mg L−1. The corresponding average P removal was 68 and 59% with residual concentrations of 2.32 and 1.75 mg L−1. The semi-continuous operation produced a rapidly settleable MAAS under iron flocculated condition with a settling velocity of 92–106 m h−1 and sludge volume index of 31–43 ml g−1 in the studied cases.
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| 8. |
- Apler, Anna, 1980-, et al.
(författare)
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Distribution and dispersal of metals in contaminated fibrous sediments of industrial origin
- 2019
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 215, s. 470-481
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Tidskriftsartikel (refereegranskat)abstract
- Industrial emissions can impact aquatic environments and unregulated discharges from pulp and paper factories have resulted in deposits of cellulose fiber along the Swedish coast. These deposits are contaminated by metals, but due to their unique fibrous character the extent of sorption and dispersal of the metals is unclear. Fibrous sediments were sampled at two sites in the Ångermanälven river estuary, Sweden. The partitioning of metals between the sediment, pore water and bottom water was investigated and the degree of bioavailability was evaluated. The levels of metals in the sediment were high in fibrous or offshore samples, depending on the metal, whereas the levels of dissolved metals in pore water were low or below the limit of quantification. Partition coefficients (KD) showed that sorption to the sediment was stronger at one of the fibrous sites, possibly related to the type and size of organic matter. Undisturbed bottom water samples contained low levels of both dissolved and particle bound metals, but when comparing measured metal concentrations to threshold values of ecological status and ecotoxicological assessment criteria, both sediments and bottom water may be detrimental to living organisms. In-situ re-suspension experiments showed that the concentrations of particle bound metals increased whereas the dissolved concentrations decreased. The analyzed metals are probably retained by the solid phases of the fibrous sediment or adsorbed to particles in the water, reducing their bioavailability.
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| 9. |
- Assefa, Anteneh, et al.
(författare)
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Sources of polychlorinated dibenzo-p-dioxins and dibenzofurans to Baltic Sea herring
- 2019
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 218, s. 493-500
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Tidskriftsartikel (refereegranskat)abstract
- Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in herring (Clupea harengus) remain high in several parts of the Baltic Sea, despite declines in PCDD/F emissions since the 1980s. The reasons behind this are not well understood. This study applied a statistical modeling approach where sources of PCDD/Fs that contaminate Baltic biota were quantitatively assessed by analyzing existing datasets. PCDD/F patterns were extracted from a herring dataset using positive matrix factorization (PMF). The extracted biota patterns were transformed into sediment patterns using fish-to-sediment transformation factors, and the resulting patterns were compared with known source PCDD/F patterns. The model distinguished three model patterns, which explained 85% of the data. These patterns were matched to tetra-chlorophenol (TCP), penta-chlorophenol/atmospheric background (PCP/AB), and thermal source patterns, respectively. The thermal source was the largest contributor to toxic equivalents (TEQ) in herring, but the level decreased from 42 ± 9.0 pg TEQ g−1 lipid weight (lw) before year 2000 (pre-2000) to 15 ± 2.4 pg TEQ g−1 lw post-2000, i.e., a decline of around one-third in the original TEQ concentration. The contribution of TCP more than doubled, from 2.1 ± 0.62 pg TEQ g−1 lw to 5.6 ± 1.1 pg TEQ g−1 lw, and the relative contribution of PCP/AB also increased. These increasing trends suggest that, as primary air emissions of PCDD/Fs are managed and levels decline, the impact of TCP and PCP/AB sources on Baltic Sea biota will become more important over time and that PCDD/F-contaminated sites in coastal areas and marine environments require more attention.
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| 10. |
- Augustsson, Anna, et al.
(författare)
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High metal reactivity and environmental risks at a site contaminated by glass waste
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 154, s. 434-443
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Tidskriftsartikel (refereegranskat)abstract
- This study addresses the reactivity and risks of metals (Ba, Cd, Co, Cr, Cu, Ni, Pb, Zn, As and Sb) at a Swedish site with large glass waste deposits. Old glassworks sites typically have high total metal concentrations, but as the metals are mainly bound within the glass waste and considered relatively inert, environmental investigations at these kinds of sites are limited. In this study, soil and landfill samples were subjected to a sequential chemical extraction procedure. Data from batch leaching tests and groundwater upstream and downstream of the waste deposits were also interpreted. The sequential extraction revealed that metals in <2 mm soil/waste samples were largely associated with geochemically active fractions, indicating that metals are released from pristine glass and subsequently largely retained in the surrounding soil and/or on secondary mineral coatings on fine glass particles. From the approximately 12,000 m(3) of coarse glass waste at the site, almost 4000 kg of Pb is estimated to have been lost through corrosion, which, however, corresponds to only a small portion of the total amount of Pb in the waste. Metal sorption within the waste deposits or in underlying soil layers is supported by fairly low metal concentrations in groundwater. However, elevated concentrations in downstream groundwater and in leachates of batch leaching tests were observed for several metals, indicating on-going leaching. Taken together, the high metal concentrations in geochemically active forms and the high amounts of as yet uncorroded metal-rich glass, indicate considerable risks to human health and the environment.
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